Mechanics tu darmstadt

Got admit at mechanics at tu darmstadt for this winter ‘25 semester on 8 sept. The thing is I can only apply for visa on 12th sept, since I just now sorted out finance for blocked account. The semester begins at oct 1st and lecture at 13th oct, so if my visa gets delayed I would probably miss few weeks of lecture. The thing is i the programme is math intensive and I am a person who is weak in math, the delay might put me in a bad position. Also, I do not know if this course is a correct fit for me as it is the only admit I got

I am unaware and overwhelmingly anxious about what to do with this situation. Provide your thoughts on this!